The EAGeR study is a multi-site, double-blinded randomized trial designed to assess the effects of low-dose aspirin on implantation and pregnancy outcome. It is the largest such study to-date, enrolling 1,228 (535 in the low-dose aspirin group and 543 in the placebo group) women experiencing a recent pregnancy loss who are planning subsequent pregnancies. Daily urine samples were collected to monitor very early pregnancy and pregnancy loss. Pregnancy loss, pregnancy complications and perinatal outcomes were monitored throughout pregnancy. We hypothesized that low-dose aspirin may reduce oxidative stress and inflammation and, therefore, reduce vascular resistance and improve blood flow and placental perfusion. Aspirin might have antioxidant properties and plays an important role in inflammation. It will be the largest such study to-date, enrolling 1,600 women experiencing a recent pregnancy loss who are planning subsequent pregnancies. We hypothesize that low-dose aspirin may reduce oxidative stress and inflammation and, therefore, reduce vascular resistance and improve blood flow and placental perfusion. An increased supply of oxygen and nutrients should promote placental and fetal growth, enhance conception rates, reduce pregnancy loss and pregnancy complications and, thereby, improve perinatal outcomes. Findings from this trial will have important implications not only for women trying to conceive but also for women who want to maintain a healthy pregnancy and achieve optimal perinatal outcomes. Supports Z1AHD008795